Large scale culture technique for pure Plasmodium falciparum gametocytes.

A large scale technique for pure gametocyte cultures of Plasmodium falciparum was established in culture flasks by using treated erythrocytes and RPMI medium supplemented with 15% human plasma instead of serum. Pure gametocyte cultures were successfully obtained following treatment with 5% sorbitol on day 8 and 9 of cultivation. This method resulted in approximately 97% reduction of asexual parasites and provided pure gametocytes in culture. The highest numbers of gametocytes were obtained from cultures starting with 2% parasitemia and 2% erythrocyte suspension. On day 12 of cultivation, approximately 35 x 10(6) gametocytes per 100 ml of cell suspension could be harvested.

Development of cultivation technique for pure Plasmodium falciparum gametocytes.

Pure gametocyte culture of Plasmodium falciparum, isolate KT3, from Kanchanaburi Province, Thailand, was successfully established by 5% sorbitol treatment on days 9, 10 and 11 following initiation of culture. Using medium supplemented with 15% human plasma and activated erythrocytes, daily medium change was not required during the cultivation. There was 99% reduction in the numbers of asexual parasites in the culture but the numbers of gametocytes were not affected. Furthermore, the gametocytes could undergo their usual morphological development with retention of function as demonstrated by the appearance of exflagellating microgametocytes, macrogametocytes and of oocyst formation in midgut of infected mosquito.